When in worry, when in doubt,
Yell and scream and rush about.
When in danger, when in doubt,
run in circles, scream & shout.
2: Stop leak: turn off mains water inlet taps
3: Stop leak: turn off affected tap if possible
I think that you've got number three the wrong way round. Whether the affected tap is open or closed will make no difference to the water coming out of the leak. However, once you turn off the main water inlet taps, you then need to turn the affected tap on (and turn all other taps on) so that you can drain the water that is in the system out as fast as possible.